The invention relates to a method and device for coupling and uncoupling cylinders in a printing press.
DE 195 37 421 C1 discloses a method and apparatus for disconnecting a cylinder from a drive which includes a coupling consisting of first and second clutch disks. The first clutch disk is connected without rotational play to a drive wheel and the second clutch disk is connected without rotational play to the cylinder journal. Both clutch disks can be axially shifted with respect to each other by means of a work cylinder to which pressure can be applied. In the process, a lower pressure is applied to the work cylinder during the coupling process than the final pressure which is applied in the coupled state. The first clutch disk is connected with a control valve whereby the control valve can be actuated by the second clutch disk in such a way that during the coupling of the work cylinder, the control valve contains a pressure medium and the control valve is closed in the coupled state.
EP 0 714 767 A1 discloses a device for coupling a rotatary cylinder in a printing machine where a drive wheel is fixed during the removal of the cylinder. The cylinder journal of the rotatary cylinder is arranged in the frame, formed by two half-shells, in an openable bearing. The bearing is provided with a bore in a bearing bushing, where the bore is concentric with the cylinder axis. A hollow shaft rotates in the bore without play, and a control shaft that can be axially displaced is arranged in said hollow shaft where each control shaft and the associated cylinder journal are connected by means of coupling halves. On the end, the drive wheel is attached to the hollow shaft, and between the hollow shaft and the control shaft, an additional gear is arranged, with clearance, which compensates for shaft misalignment. The hollow shaft has internal teeth, and the control shaft has two external sets of teeth that cooperate with the internal teeth, and can be rotated with respect to each other.
DE 296 17 401 U1 discloses a device for the connection/disconnection of roller elements of a printing machine. By the axial shifting of a journal, using a tensioning spindle which passes through the roller body, the coupling of the roller and bearing is achieved. On one side, the tensioning spindle can be screwed into the first journal, and, one the other side, a tensioning screw passes through a second journal and can be screwed into the tension spindle. The roller body presents, on the front side, passage bores for receiving the journal where compression springs are arranged in the passage bores can be connected to the roller body by the actuation of the tensioning screws of both journals against the spring force. A drawback of this arrangement is that all of the embodiments are relatively expensive.
It is an object of the present invention to provide a method and apparatus which avoids the drawbacks of the prior art and which enables efficient coupling and uncoupling of cylinders and bearings, while simplifying the drive and reducing equipment installation times.
A first advantage of the method and apparatus of the invention is that the coupling process can be automated. As a result, a considerable reduction of installation time can be achieved in the replacement of a cylinder in a printing machine.
Another advantage is that the coupling and decoupling of the cylinder can be carried out rapidly and reliably and that a high rotational precision can be achieved by centering the cylinder.
An additional advantage is that the cylinder can be designed with or without a journal. A recess for the journals which penetrates the lateral frame is not necessary.
This simplifies the insertion or the replacement of the cylinder between two lateral frame walls, regardless of whether the operations are carried out manually or in automated fashion, for example, by means of a magazine and/or handling device, or industrial robots.
Finally, it is advantageous that a replacement of the cylinder, or alternately, of a roller, can be carried out in a manual or automated process. For example, in printing and/or coating machines, an automated replacement of the printing/coating block can be carried out, while an automated replacement of cylinders or rollers in the bearing bushings is carried out, preferably simultaneously.